crznZ06

When does it become beneficial to start tuning your own car? I'm considering getting my '03 coupe with ARH headers and Vararam dyno tuned, but I'm wondering if it would be better to just learn how to tune the car myself.

I mainly use my car for auto crosses and hard canyon driving - mostly second and third gears. Full throttle is great, but I spend a LOT of time between (guessing...) 50% and 99% throttle when working corners. Sometimes, when I'm scooting around traffic, I short shift the car, and lug the car a little, so I'm not getting it squirrely everywhere. My feeling is that, aside from getting a number to throw around to impress people, a dyno does not represent the way I'm going to drive the car. Am I wrong?

How difficult is it to tweak fan temperatures, turn off torque management, and turn off the check engine light from deleting the rear 02 sensors? I'm guessing not...

How difficult is it to data log and tweak the part throttle maps so there are no dead spots, spikes, hiccups, etc?

What tuning hardware and software is a good place to start? My headers look like they have a provision for a wide band 02 sensor. Is it worth getting a tablet to run the tuning software? I've seen HPTuners and EFI Live - are there any other programs I should be looking into?

I appreciate your thoughts.

Fractional Pursuit

Sorry I am not a Corvette expert, yet. Came from the world of imports were tuning is so very important to keep those small turbo motors alive. Manufactures tune a car so that it will work for every car (same model). They have to meet emissions and last at least to the end of warranty. The tune is for the parts that make up that car. When you change parts it will run different and need a different calibration to make it run properly. There is also power left on the table so that the car is reliable. Tuning a car lets you cut into that reliability and allows you to tune to just that one car.

I am not a tuner, but I have dabbled enough to know its not something you will pick up in an evening. Tuning is not hard, but it will take a lot of experience and knowledge to get it right. Guess what happens if you get it wrong.
If tuning looks interesting and something you would like to pursue then there are reasonable classes you can take were someone can walk you through it. What is a proper Air/Fuel ratio for max load? no load? coasting? emissions? What would a good timing curve look like? where do I start. Dyno no Dyno? Once you get the knowledge and the notebook then you could tune your car. Why go through all that just for one car-yours unless that is something that you are really interested in.

I thought of buying a class and the software, and get a lot of the questions answered with a one on one with an instructor. Its not crazy expensive, but the catch is it takes a lot of time. I have had good luck with online tunes and had a copy of the software to tweak things later. Example: Tuner tunes car online. I take car to the track and it hits boost cut (overboost). I can tweak either the turbo boost or the cutoff to make it run better.

Not a perfect explanation, but I hope you get the point.

romandian

what you are asking is not difficult. is it worth it? no idea. people spend thousands on their hobbies, so why not get the hard and software and see what it does? much will depend on how much you know about engines and tuning. of course if your main concern are the fans, there are simpler ways to do it. but i guess you have made up your mind and are looking for back up. go ahead.

much could be said, just two things: i doubt that tweaking the part throttle maps with seat of the pants feedback will yield any noticable results. and our engine responds very lazily to timing changes, so gains on an almost stock configuration are very limited.

NSFW

I think a lot of it depends on just a few things...

How comfortable are you working with numbers? Lots and lots of numbers. I never had much luck tuning engines with carburetors, and tuning my Subaru electronically seemed much easier - working with tables of numbers just came much more naturally to me than working with jets and valves and things that interact in various mysterious ways.

How motivated are you to learn? If your primary goal is to have a fast car, paying for a tune will get you there faster. If you really really want to know more about how engines work and how engine computers work, then tuning your own car will give you lots of opportunities to find problems, search for answers, figure stuff out, test theories, verify results, and so on.

How much time are you willing to spend on it? Both in terms of hours spent making logs, studying logs, figuring out what to change in the tune... and in weeks (or probably months) that will elapse before you're satisfied.

It all took far longer than just paying for a tune, but it was a fun process and I learned a ton about how engines and engine computers work. I enjoyed the process with my Subaru and I'm looking forward to starting over with a Corvette.

Joshboody

I have some BMW tuning experience, but LS is much different. If you have engine knowledge than no prob to understand the concepts. But learning the software and ECU parameters will take much time.

One of the first things I did was downloaded stock tune, and scanned the stock engine then slowly started tinkering. Eventually tuned ethanol and now just installed a cam, so my first major tuning experience. Due to my slow progression, its quite easy... but I do make some minor miscalcs occasionally that can take awhile to figure out.

Great communities in CF, ls1tech, and HPT to help out also. Except for the darn injector flow rates and offsets

Gordy M

When tuning a LS engine you should look at your end goal first. If you are going to only add headers/CAI then do not go to the trouble of learning to tune. Get a great scan/log tune and be done with it. A good tuner can change the intermediate values to give you great pick up, eliminate the TB delay without making it undriveable, etc. Stay away from the tuner who would make the high/lo tables the same values, only look for max hp, etc. You want a Corvette that is responsive, streetable and will not self destruct. Personally I would make sure they have done more than 1,000 tunes or more before I would use them. If you are going to drag race it extensively, add NO or Boost, then a dyno tune might be more beneficial.

If you want to go the self tune route, then EFI Live and HP Tuners are great products with forum members that can help you with tuning problems.

romandian

dont get obsessed with injector data. anyting can be made to work actually.

Joshboody

Sure, but the right #s makes the tune more solid. Not so much the flow, but offset seems to be a big deal if there's much diff between injectors... #s I've seen (if accurate) would make a considerable diff at idle/cruise.

Podium

Having the correct injector data will help tune the car correctly. You can end up chasing your tail with out correct data.

nsogiba

subscribed, I just picked up HPTuners and am looking to start learning on how to optimize the tune for the cam'd L92 going in my C5.

Supercharged111

Only thing you can't do without a dyno is tune for max hp. Everything else can be done on the street. VE and MAF are as simple as copy/paste with multiply, go log again. Low end timing can be felt with seat of the pants as the factory generally beings it in too slowly, but the total WOT timing on a Z06 looks decent to me. There was not the low hanging fruit on the Z that you could find in the other motors of that era, especially the truck engines. Boy is it wasy to impress a guy with a flash on a Gen III truck engine.

NSFW

Are the factory C5 engines knock-limited at full throttle? I mean, if you steadily advance the timing, do you start knocking before you reach the peak torque? (for a given RPM/airflow/AFR)

The reason I ask is that, if they are, then I suspect you can get reasonably close to max HP by picking a reasonable AFR, advancing timing up to the knock threshold, and then backing it down for a margin of safety. That approach gave good enough results with my Subaru that I didn't bother with a dyno tune (377whp with an old GT3076R turbo, which is comparable to what the pros were getting from similar setups).

Supercharged111

I'm inclined to say no, but I'm not sure in that. I want to say that, at 6000' altitude, an LS6 tends to want about 30 degrees of advance. I believe that would put it around 26 at sea level? And I want to say that's about what they command stock? Haven't been in the tune in a while. I leaned mine out in PE mode and when I get it back intend to experiment with bringing the existing timing in a bit sooner. I'm a nerd who likes to lug around at low RPM most of the time.